HLA DRB3*0101 typing was carried out in 198 of the 210 immunized women and 18 were found to be HLA DRB3*0101 negative. Of the 154 women who followed the screening and intervention program, 150 were typed for the presence of HLA DRB3*0101, of whom 12 were HLA DRB3*0101 negative. Only 2 of these 12 women gave birth to thrombocytopenic children (platelet counts, 59 × 109/L and 94 × 109/L)